1. Field of the Invention
The present invention relates generally to aerogenerators and, more particularly, to an aerogenerator in which a rotation support unit for enabling a rotational body to rotate on an upper end of a support pillar reduces a contact area between the rotational body and the support pillar, thus making it possible to more smoothly rotate the rotational body in the direction in which the wind is blowing.
2. Description of the Related Art
As well known to those skilled in the art, aerogenerators are one kind of generators which obtain rotating force in such a way as to rotate vanes using naturally-occurring wind, convert the rotating force into electric energy, and supply the produced electricity to areas where it is needed.
Such an aerogenerator includes a support pillar, rotational bodies and vanes. The support pillar is placed upright on the ground.
The rotational body is rotatably provided on the upper end of the support pillar, and the vanes are supported by the rotational body and provided on respective opposite ends of the upper end of the support pillar. The vanes generate rotating force using the wind.
In the aerogenerator having the above-mentioned construction, the rotational body is rotated depending on the direction of the wind such that the vanes are easily oriented facing in and away from the direction in which the wind is blowing, so that the vanes can be more effectively rotated by the wind.
Recently, aerogenerators have been used which include a pair of vanes and which are constructed such that a rotational body is rapidly rotated in the direction in which the wind is blowing so as to increase rotating force of the vanes.
FIG. 1 is a view illustrating a conventional aerogenerator.
As shown in the drawing, the conventional aerogenerator 1 includes a support pillar 10 which is placed upright on the ground, a rotational body 20 which is rotatably provided on the upper end of the support pillar 10, and two vanes 30 which are rotatably provided on the respective opposite ends of the rotational body 20.
Furthermore, a generating unit 40 is provided in the support pillar 10 or on the ground. A rotating force transmission unit 50 which increases the rotating force of the vanes 30 and transmits it to the generating unit 40 is provided in the rotational body 20.
The transmission unit 50 is disposed at an upper position in the central portion of the rotational body 20 and connects rotating shafts 32 of the vanes 30 to a rotating shaft 42 connected to the generating unit 40. The transmission unit 50 is protected by a cover 22.
Furthermore, a rotation support unit 60 is provided between the rotational body 20 and the support pillar 10. The rotation support unit 60 includes a rotating plate 62 and a plurality of rollers 64 which are provided on the rotating plate 62 and arranged in a circumferential direction. Thus, the rotational body 20 is supported on the upper end of the support pillar 10 so as to be rotatable using the rotation support unit 60.
Due to the above-mentioned construction, the rotational body 20 having the vanes 30 is easily rotated in the direction in which the wind blows, so that the rotating force of the vanes 30 can be increased, thus enhancing the amount of produced electric energy.
However, in the conventional aerogenerator 1, each of the rollers 64, which rotate in the circumferential direction around the center of the rotating plate 62, has a frusto-conical shape. Thus, the contact area of the rollers 64 with the rotational body 20 and the support pillar 10 is relatively large, with the result that the friction therebetween is increased.
Due to relatively high friction, not only the circumferential outer surface of the rollers 64 but also the surfaces of the rotational body 20 and the support pillar 10 get worn with the passage of time. As a result, the rotational body 20 cannot smoothly rotate on the support pillar 10. Thereby, the rotational body 20 cannot rapidly rotate in the direction in which the wind is blowing, thus reducing the efficiency of producing electric energy.